Overhead doors for use with mobile trailers for over-the-road trucks and utility vehicles, as well as for stationary applications, are well known and widely used. Typically, such overhead doors are commonly placed at the loading end of a cargo bay of a trailer or of a stationary cargo bay such as a garage or storage locker and are sized and shaped to enclose an expansive opening having significant height and width dimensions. Typically, such overhead doors are constructed of wood, fiberboard composite, or sheet material such as sheet metal. As is well known in the art, such construction offers good structural stability and generally weather resistant qualities. In the installed condition, overhead doors are fabricated with a plurality of horizontally arranged panel portions or slats engaged in a contiguous arrangement at the opposing upper and lower horizontal edges thereof so as to provide an articulating door structure which may be rolled into a overhead compartment of the trailer to which it is installed. Such doors also include track-engaging rollers at the outboard vertical edges of the panel portions and are slidably or rollably engaged with parallel tracks mounted adjacent to and frame the vertical extent of the opening of the loading end of the trailer.
During opening and closing operations and in the open and closed positions, overhead doors and especially the track-engaging rollers and attachment hardware therefor are subject to high loading and retention forces, and are further subjected to continuing shock and vibration loads in the case of mobile applications such as during over-the-road transport. When the door is in the closed position, the track-engaging rollers are subject to transverse loadings caused by shifting loads imparting substantial loads against the closed door. Furthermore, such overhead doors and their roller apparatus are subject to impact loading with objects extending in the path of the closing or opening door. Furthermore, overhead doors of the prior art construction are subject to harsh environmental factors including humidity, heat and cold, all of which over time compromise the structural integrity of the material from which the door is fabricated.
In view of the above, overhead doors, and especially those portions of the overhead door panels to which track-engaging rollers are affixed, are subject to failures and weaknesses at those areas subject to stress, especially in the areas of the track-engaging rollers and other attachment hardware. Such failures and weaknesses result in cracks, separations and deterioration of the panel portions supporting the track-engaging rollers and attachment hardware.
In particular, it is not uncommon for trailer overhead door panel portions to require regular and even daily repair or replacement due to weakened and broken lower panel corners resulting in the breakage or loss of the rollers affixed thereto, or of intermediate panel portions which are likewise affected by adverse environmental and service conditions such that interconnecting hinges and underlying panel sections are damaged or separated from the door structure. Accordingly, such damage has heretofore upset tight shipping schedules by removing the trailer from service for a period of hours or even days until repairs or replacement may be made to damaged door panel portions or related hardware. This problem is especially critical in view of rigorous scheduling requirements whereby trailers are under demanding time schedules and loads must be delivered on time, providing little or no time for replacement or repair of such damaged portions of the overhead doors. In the instance where such repair or replacement is essential to the integrity to the trailer, the affected trailer is typically remove from fleet service for a matter of hours during which time a panel portion or even the entire door is removed for repair or replaced with another door portion.
One approach to overcoming this problem involves the time-consuming procedure of removing the damaged portion of the door together with the mounting hardware and custom fitting a handcut piece of sheet material such as sheet metal to the door portion in need of repair. Although such damage to be repaired is generally confined to the particular lower corners of the doors or to the attachment points of the hardware at intermediate sections of the overhead doors, each repair using this patching method necessarily requires time to custom cut and fit the sheet material patch to the damaged area followed by attachment of the roller hardware to the patched area. Accordingly, this prior art patching method is time-consuming and generally non-uniform in appearance and, without any uniformity in such patching repair, offers a non-standard repair in virtually every repair situation, thereby compromising strength and aethetic requirements originally designed into the door and roller apparatus. Another approach is the replacement of the entire affected panel portions which require maintaining a stock of such panel portions for every type of door in the trucking company's inventory, and a substantial period of down time for the trailer while the panel portion(s) is located and transported to the repair location at which time the damaged panel portion(s) are replaced as necessary.
Thus, it is desirable to provide a repair and reinforcement apparatus for an overhead door which provides uniform repair and reinforcement characteristics with a minimum of down time at a minimal cost investment in both materials and labor, and to provide such repair and reinforcement apparatus for in situ installation with a minimum amount of downtime and inconvenience to the trucking operator.